1. A 47-year-old m an com plained to his physician of an inability to m aintain an erection. After a com plete m edical workup, he was prescribed intraurethral adm inistration of alprostadil to be...

1. A 47-year-old m an com plained to his physician of an inability to m aintain an erection. After a com plete m edical workup, he was prescribed intraurethral adm inistration of alprostadil to be used before intercourse. Which of the follow ing m olecular m echanism of action m ost likely m ediated the e cacy of the drug in the patient’s erection disorder? A. Activation of prostaglandin E1 receptors B. Blockade of a1 adrenoceptors C. Activation of m uscarinic M3 acetylcholine receptors D. Blockade of throm boxane A2 receptors E. Activation of ß2 adrenoceptors F. Release of nitric oxide368 In ammation and Immunomodulation